Asian Diver – March 2018

(Steven Felgate) #1
Newborn pups measure around
60–70
centimetres

GIANT DORSAL FIN
Aside from its size, the best way to
identify a great hammerhead and
separate it from
other species is its
very high and curved
first dorsal fin

GREAT HAMMERHEAD SHARK


ENERGY CONSERVATION
A 2016 study using accelerometers
revealed that hammerhead sharks often
roll over and swim sideways in order to
save energy. Their long dorsal fin acts in a
similar way to the pectoral fins, increasing
the animal’s wingspan and allowing it to
swim approximately 10% more efficiently

REPRODUCTION
Hammerheads are viviparous; they
gestate live young via a yolk sac
placenta for 11 months before giving
birth to between 13–42 pups in a litter.
The average size of a pup at birth is
around 60–70 centimetres in length and
they have a more rounded head shape
than adults which slowly changes as the
shark reaches maturity
Shark

Ray

Squid

Lobster

Bony Fish

Crab Skate

Octopus

DIET
Great hammerheads are a nomadic predator with a preference for rays and skates.
Venomous spines of stingrays are often found lodged inside its mouth and do not seem
to prevent them from routinely targeting this type of prey. They will also consume
invertebrates such as crabs, lobsters, squid and octopus, bony fish and other sharks

PREDATORS
Juveniles are preyed upon by other
shark species such as bull and
tiger sharks, while adults have no
major predators except for orcas.
Orcas have been known to hunt
various hammerhead species
of any size

Maximum Size

Average size

Maximum Weight

6.1 metres

3.7 metres

449.5 kilograms

SCIENTIFIC CLASSIFICATION
Kingdom : Animalia
Phylum : Chordata
Class : Chondrichthyes
Subclass : Elasmobranchii
Superorder : Selachimorpha
Order : Carcharhiniformes
Family : Sphyrnidae
Genus : Sphyrna
Species : S. mokarran

CONSERVATION STATUS


Extinct Endangered Threatened

EXEWCRENVUNTLC

Orca

Bull Shark

Tiger Shark
Free download pdf